端端舝

1986-2005 ⊕ Twitter: @aomoriringo

⊕ 郔輪妏勻化月晟惤
? C#

⊕ 𧘇庤
2005-2011 ? Mathematica

2011- ⊕ Haskell窃
? 2仳堎帤㦤

⊕ 中仁勾井及憝杅支倰﹜倰弁仿旦卅升毛隅膽仄凶白央奶伙

⊕ Haskell及皿伕弘仿丞反乒斥亙奈伙及摩磁

⊕ 戊奈玉毛乒斥亙奈伙卞煦賃允月午仄丐歹六
? 婬瞳蚚俶毛詢戶月
? 奪燴?党淏仄支允仁允月

⊕ 乒斥亙奈伙毛奶件禾奈玄允月

⊕ 梓𨃨乒斥亙奈伙毛妏勻化心月
? 㻢𨃨乒斥亙奈伙匹中欠中欠釬勻化心月
? foldl, foldl＊
? 蟀砑伉旦玄

⊕ 赻煦匹乒斥亙奈伙毛釬勻化心月

乒斥亙奈伙毛奶件禾奈玄允月

⊕ �化毛奶件禾奈玄
import Data.List

⊕ nub, sort及心毛奶件禾奈玄
import Data.List (nub, sort)

⊕ nub眕俋及�化毛奶件禾奈玄
import Data.List hiding (nub)

import qualified Data.Map
? Data.Map.filter及方丹卞統桽

import qualified Data.Map as M
? M.filter及方丹卞統桽

⊕ module Foo卞hoge午bar互丐月午五
哫晟奶件禾奈玄今木月手及統桽及源楊
import Foo hoge, bar hoge, bar
Foo.hoge, Foo.bar
import Foo () (卅仄)
import Foo (hoge) hoge hoge, Foo.hoge
import Foo hiding (hoge) bar bar, Foo.bar
import qualified Foo hoge, bar Foo.hoge, Foo.bar
import Foo as F hoge, bar hoge, bar
F.hoge, F.bar
import qualified Foo as F hoge, bar F.hoge, F.bar

⊕ Data.List毛奶件禾奈玄
ghci> :m + Data.List
ghci> :m + Data.List Data.Map Data.Set

⊕ Data.List及奶件禾奈玄毛賤壺
ghci> :m 每 Data.List

⊕ import手妏蚚褫夔
ghci> import Data.List (nub, sort)
ghci> import qualified Data.Map as M hiding (foldl)

梓𨃨乒斥亙奈伙毛妏勻化心月

Data.List
Data.Char
Data.Map

⊕ Hackage
? hackage.haskell.org/packages/hackage.html

⊕ Hoogle
? http://www.haskell.org/hoogle/
? 㻢𨃨乒斥亙奈伙及末奈旦戊奈玉互�木引允

⊕ Hayoo!
? http://holumbus.fh-wedel.de/hayoo/hayoo.html

⊕ �g惤及�杅毛捼屯月

ghci> :t wordNums
wordNums :: String -> [(String,Int)]

ghci> wordNums "a haskell learn haskell a a learn good"
[("a",3),("good",1),("haskell",2),("learn",2)]

⊕ 恅趼蹈毛諾啞匹Еピ日木凶恅趼蹈及伉旦玄卞劐𡥼允月

ghci> :t words
words :: String -> [String]

ghci> words ※hey these are the words§
[※hey§, ※these§, ※are§, ※the§, ※words§]

ghci> words ※hey these are the words§
[※hey§, ※these§, ※are§, ※the§, ※words§]

⊕ 伉旦玄及肮元猁匼毛弘伙奈皿趙允月

ghci> :t group
group :: Eq a => [a] -> [[a]]

ghci> group [1,1,1,2,2,2,3,3,2,2,5,7]
[[1,1,1],[2,2,2],[3,3],[2,2],[5],[7]]

ghci> group [※hoge§, ※var§, ※var§, ※hoge§, ※hoge§]
[[※hoge§], [※var§, ※var§], [※hoge§, ※hoge§]]

⊕ 伉旦玄毛翝�卞�K屯杸尹月

ghci> :t sort
sort :: Ord a => [a] -> [a]

ghci> sort [5,4,3,7,2,1]
[1,2,3,4,5,7]

ghci> sort [※hoge§, ※var§, ※var§, ※hoge§, ※hoge§]
[※hoge§, ※hoge§, ※hoge§, ※var§, ※var§]

恅趼蹈毛�g惤卞Еピ勻化 (words)

↙末奈玄仄化 (sort)

↙弘伙奈皿趙仄化 (group)

↙弘伙奈皿仍午卞杅毛杅尹木壬

匹五公丹匹允友ㄐ

⊕ wordNums及隅膽
wordNums :: String -> [(String,Int)]
wordNums = map (?ws -> (head ws, length ws)) .
group . sort . words

ghci> wordNums ※a b c b c§
[("a",1),(※b",2),(※c",2)]

ghci> wordNums ※§
[]

⊕ 丐月伉旦玄互�e及伉旦玄卞漪引木月井升丹井毛捼屯月

ghci> :t isIn
isIn :: [a] -> [a] -> Bool

ghci> ※art§ `isIn` ※party§
True

ghci> [1,2] `isIn` [1,3,5]
False

⊕ 伉旦玄卞�仄化tail毛靜曰殿仄羥蚚允月

ghci> :t tails
tails :: [a] -> [[a]]

ghci> tails ※party§
[※party§, ※arty§, ※rty§, ※ty§, ※y§, ※§]

ghci> tails [1,2,3]
[[1,2,3], [2,3], [3], []]

⊕ 2勾醴及伉旦玄互1勾醴及伉旦玄匹
宎引勻化中月井升丹井毛殿允
ghci> :t isPrefixOf
isPrefixOf :: String -> String -> Bool

ghci> ※hawaii§ ìsPrefixOf` ※hawaii joe§
True

ghci> ※haha§ ìsPrefixOf` ※ha§
False

ghci> ※ha§ ìsPrefixOf` ※haha§
True

※art§ ìsPrefixOf` ※party§ -- False

※art§ ìsPrefixOf` ※arty§ -- True

※art§ ìsPrefixOf` ※rty§ -- False

※art§ ìsPrefixOf` ※ty§ -- False

※art§ ìsPrefixOf` ※y§ -- False

⊕ 伉旦玄及丹切﹜扴惤毛㦤凶允手及互丐月井升丹井毛殿允

ghci> :t any
any :: (a -> Bool) -> [a] -> Bool

ghci> any (>4) [1,2,3]
False

ghci> any id [False, False, True]
True

⊕ isIn及隅膽
isIn :: (Eq a) => [a] -> [a] -> Bool
needle `isIn` haystack =
any (needle `isPrefixOf`) (tails haystack)

needle: �﹝�勾仃凶中伉旦玄
haystack: 補仄翌及刓﹝𨈘坰�砓及伉旦玄

⊕ Data.List.isPrefixOf
? ゴ源珨祡
? 今勻五妏勻凶

⊕ Data.List.isSuffixOf
? 摽源珨祡

⊕ Data.List.isInfixOf
? 笢嶲珨祡
? 今勻五釬勻凶(isIn)

⊕ 扑奈扒奈做瘍
? ⅸ恅及跪恅趼毛棗𤩸�卞n恅趼扑白玄仄化釬月

⊕ 恅趼<->Unicode劐𡥼
ghci> :t ord
ord :: Char -> Int
ghci> ord ＆a＊
97

ghci> :t chr
chr :: Int -> Char
ghci> chr 97
＆a＊

ghci> map ord ※abcdefgh§
[97,98,99,100,101,102,103,104]

⊕ 硌隅仄凶恅趼杅煦扑白玄允月
encode :: Int -> String -> String
encode offset msg =
map (?c -> chr $ ord c + offset) msg

⊕ 硌隅仄凶恅趼杅煦欄卞扑白玄允月
decode :: Int -> String -> String
decode shift msg = encode (negate shift) msg

ghci> encode 3 ※hey mark§
※kh|#pdun§

ghci> decode 3 ※kh|#pdun§
※hey mark§

ghci> decode 3 $ encode 3 ※abc§
※abc§

⊕ 跪鳻及杅及磁�互n卞卅月郔場及赻�杅毛心勾仃月

ghci> :t firstTo
firstTo :: Int -> Int

ghci> firstTo 1
1

ghci> firstTo 13
49

⊕ 恅趼毛杅卞劐𡥼允月

ghci> :t digitToInt
digitToInt :: Char -> Int

ghci> digitToInt ＆2＊
2
ghci> digitToInt ＆F＊
15
ghci> digitToInt ＆z＊
*** Exception: Char.digitToInt: not a digit 'z'

⊕ 跪鳻及杅及睿毛殿允

digitSum :: Int -> Int
digitSum = sum . map digitToInt . show

ghci> digitSum 30
3
ghci> digitSum 1234
10

ghci> :t find
find :: (a -> Bool) -> [a] -> Maybe a

ghci> find (>4) [3,4,5,6,7] Nothing | Just a
Just 5

ghci> find odd [2,4,6,8,9]
Just 9

ghci> find (==＆z＊) ※haskell§
Nothing

⊕ firstTo及隅膽
firstTo :: Int -> Maybe Int
firstTo n =
find (?x -> digitSum x == n) [1..]

ghci> firstTo 27
Just 999

ghci> firstTo 40
Just 49999

ghci> foldl (+) 0 [1..2000000]
2000001000000
? 綈中
? 扔奶朮﹜虐噫卞方勻化反旦正永弁左奈田奈白伕奈

ghci> Data.List.foldl＊ (+) 0 [1..2000000]
2000001000000
? foldl方曰厒中
? 左奈田奈白伕奈仄卅中

foldl (+) 0 [1,2,3] =
foldl (+) (0 + 1) [2,3] =
foldl (+) ((0 + 1) + 2) [3] =
foldl (+) (((0 + 1) + 2) + 3) [] =
((0 + 1) + 2) + 3 =
(1 + 2) + 3 =
3 + 3 =
6

⊕ 淏跡卅(綈晊匹卅中)酘�心煋心

foldl＊ (+) 0 [1,2,3] =
foldl＊ (+) 1 [2,3] =
foldl＊ (+) 3 [3] =
foldl＊ (+) 6 [] =
6

⊕ 氝趼午仄化￤砩及倰毛妏蚚允月饜蹈

⊕ 網太源反中欠中欠
? Map
? Dictionary
? Hash

⊕ 正皿伙毛蟀砑伉旦玄勻弔仁㜳丹
ghci> :t lookup
lookup :: Eq a => a -> [(a,b)] -> Maybe b

ghci> lookup ※b§ [(※a§,1), (※b§,2), (※c§,3)]
Just 2

ghci> lookup ※k§ [(※a§,1), (※b§,2), (※c§,3)]
Nothing

⊕ 蟀砑伉旦玄(Map)及乒斥亙奈伙
? Data.Map.lookup
? Data.Map.insert
? Data.Map.delete
? Data.Map.size
? etc..

⊕ Data.Map匹蟀砑伉旦玄毛桶允倰
⊕ key午value及倰毛厥勾

ghci> let m = Data.Map.fromList [(※foo§,1), (※bar§,2)]
ghci> :t m
m :: Data.Map.Map [Char] Integer

ghci> let m2 = Data.Map.fromList [(＆a＊, True), (＆b＊, False)]
ghci> :t m2
m2 :: Data.Map.Map Char Bool

ghci> import qualified Data.Map as Map

⊕ key匹𨈘坰允月
ghci> let m = Map.fromList [(※a§,1), (※b§,2)]
ghci> Map.lookup ※b§ m
Just 2
ghci> Map.lookup ※c§ m
Nothing

⊕ key=※c§, value=3及猁匼毛浲⻌允月
ghci> let m2 = Map.insert ※c§ 3 m
ghci> Map.lookup ※c§ m2
Just 3

ghci> Map.size m2
3

⊕ value卞憝杅毛羥蚚仄化陔仄中Map毛釬月

ghci> m2
fromList [("a",1),("b",2),("c",3)]

ghci> Map.map (^2) m2
fromList [("a",1),("b",4),("c",9)]

ghci> Map.map show m2
fromList [(※a§,§1§), (※b§,§2§), (※c§, ※3§)]

⊕ key互笭恚仄凶蕣及淥月敃中毛𢜪戶月

ghci> Map.fromList [(1,2),(1,50),(1,10),(2,3)]
fromList [(1,10),(2,3)]

ghci> Map.fromListWith (+) [(1,2),(1,50),(1,10),(2,3)]
fromList [(1,62),(2,3)]

ghci> Map.fromListWith max [(1,2),(1,50),(1,10),(2,3)]
fromList [(1,50),(2,3)]

⊕ 珂螹卞乒斥亙奈伙哫晟毛𤩸仁
-- Foo.hs
module Foo where

? 乒斥亙奈伙靡午白央奶伙靡反肮元卞仄卅仃木壬卅日卅中

⊕ 乒斥亙奈伙及笢旯毛
? �化鼠嶱仄凶中(巨弁旦禾奈玄)
module Foo where

? 珨窒分仃鼠嶱仄凶中
? module Foo (hoge, var) where

⊕ test1/Nums.hs
module Nums where

double x = x + x
quadruple x = double x + double x

⊕ test1/Main.hs
import Nums

double2 = Nums.double 2
quadruple4 = Nums.quadruple 4

⊕ test1/Nums.hs
module Nums (double) where

double x = x + x
quadruple x = double x + double x

⊕ test1/Main.hs
import Nums

double2 = Nums.double 2 -- OK
quadruple4 = Nums.quadruple 4 -- 戊件由奶伙巨仿奈

⊕ 乒斥亙奈伙反蕆𦵴�婖毛厥勾仇午互褫夔

⊕ 蕆𦵴�婖反☆A.B.C★及方丹卞玉永玄☆.★匹桶允

⊕ A.B.C午中丹乒斥亙奈伙靡卞仄凶�磁反﹜
A/B/C.hs午中丹白央奶伙�傖卞允月

⊕ test1/Figure/Sphere.hs
module Figure.Sphere where
Area radius = 4 * pi * (radius ^ 2)

⊕ test1/Figure/Rectangle.hs
module Figure.Rectangle where
Area width height = width * height

⊕ test1/Main.hs
import qualified Figure.Sphere as Sphere
import qualified Figure.Rectangle as Rect

sphereArea = Sphere.Area
rectArea = Rect.Area

⊕ 奶件禾奈玄, 巨弁旦禾奈玄反升切日手��毛癹隅匹五月

⊕ 㻢𨃨乒斥亙奈伙毛捼屯月, 妏丹, 燴賤允月扔奶弁伙毛
旯卞勾仃凶中

⊕ ☆仇氏卅及卅中井卅ˋ★午佷勻凶日Hoogle午井匹抻允

⊕ 乒斥亙奈伙及巨弁旦禾奈玄毛𠸎卞仄化五木中卅戊奈玉毛
𤩸五凶中匹允友

端端舝

允仍中Haskell㜭仄仁悝廿丹菴6梒

Recommended

More Related Content

What's hot (20)

Viewers also liked (20)

Similar to 允仍中Haskell㜭仄仁悝廿丹菴6梒 (20)

More from aomori ringo (7)

允仍中Haskell㜭仄仁悝廿丹菴6梒

端端舝

允仍中Haskell㜭仄仁悝廿丹 菴6梒

Recommended

More Related Content

What's hot (20)

Viewers also liked (20)

Similar to 允仍中Haskell㜭仄仁悝廿丹 菴6梒 (20)

More from aomori ringo (7)

允仍中Haskell㜭仄仁悝廿丹 菴6梒

允仍中Haskell㜭仄仁悝廿丹菴6梒

Similar to 允仍中Haskell㜭仄仁悝廿丹菴6梒 (20)

允仍中Haskell㜭仄仁悝廿丹菴6梒